Endurance: marine engineering a century ago

This month, as we mark the centenary of Ernest Shackleton’s Endurance expedition, Petty Officer Seb Coulthard of the Royal Navy reflects on the marine engineering skills of a hundred years ago.

Seb Coulthard is a man with an obsession. That obsession is a small boat called the James Caird that briefly went into action exactly a century ago. It played a crucial role in a rescue operation that ensured the crew of Ernest Shackleton’s lost ship Endurance would return to Britain without the loss of a man. Had Endurance never sunk, we almost certainly would never have heard of the James Caird and the Portsmouth-based sailor would have more time on his hands.

Coulthard serves in the 1710 Naval Air Squadron, which is the Ministry of Defence centre of expertise for aircraft repair, scientific support and ‘service modification’, the last of which Coulthard manages. In layman’s terms, he’s an engineer, more specifically an ‘expedition engineer’, the point of which he describes as “making equipment work. If you go out to a remote part of the world using boats or aircraft, you’re going to need someone to look after them. You need to be able to repair equipment on-the-go with limited or no resources. You need this knowledge and understanding of the equipment before you depart”.

To do this “you have to remove all the layers of complication, so that if you do get caught out in the middle of nowhere – and it has happened to me – you have the ability to fix whatever it is that is broken”.

An example of this is in 2013, when Coulthard was the expedition engineer on a recreation of Shackleton’s epic voyage in the James Caird. He describes how, in the middle of the Southern Ocean, in a 23ft (7m) wooden replica boat, one of the few concessions to the digital age – a mast-mounted satellite tracker – gave up its ghost. “It just stopped beeping, which meant that our support vessel couldn’t keep an eye on where we were. When it failed, everyone looked at me and expected me to fix it. But I’m a mechanical and not an electrical engineer.”

Despite this, Coulthard did the obvious thing and took it apart. “In the end I stripped a few wires, twisted the ends together and there were a lot of sparks. A few seconds later the unit came back to life.”

The critical issue here is that Coulthard had made an earlier point of observing the engineers who installed the equipment: “I gave them the spec of what I wanted and I watched them fit it. That’s why, as an expedition engineer, you need to familiarise yourself with all the equipment very early on.”

Close call with history

Coulthard has as much reason as any to join in with the Endurance centenary commemorations, which will culminate in a memorial service at Westminster Abbey in the presence of the Princess Royal. Quite apart from being one of the six-strong crew on the 2013 reconstruction, he also played a central role in the construction of the expedition replica called the Alexandra Shackleton at the International Boatbuilding Training College in Lowestoft.

Not only that, but Coulthard is currently building another replica: a process in which he intends to discover the answers to a screed of technical questions that arose on the voyage.

The main reason for Shackleton embarking on what is now regarded as one of the greatest boat journeys in history was, of course, to rescue his men. Since nobody knew where they were and there was no way of raising the alarm from their base at Elephant Island, they were compelled to make an 800-mile (1,300km) trip to fetch help for themselves. The trip took 17 days and it was nothing short of a miracle that no one died. Yet what really fascinates Coulthard is the technical background narrative. “When you pick up books on the subject, you tend to read that Endurance sinks, and the men camp out on the ice for months on end, their food runs out apart from a limited supply of dried provisions that they are saving for a boat journey which they know is going to come at some point.”

This over-simplification of the story is correct in that it emphasises the men’s dependency on the three lifeboats and the food cache, but there is so much more to it than that.

Coulthard sidetracks to explain that there were actually five boats on Endurance: “two of them – a motor boat and a skiff – have been written out of history.” The journey Shackleton eventually decided upon was the hazardous ocean crossing to South Georgia, where he knew of a whaling station at Stromness.

The boat selected out of the three for the journey was the largest and best built: the James Caird. At this point I interrupt Coulthard to ask why the journey was necessary at all, as it is well known that Shackleton had a radio set aboard Endurance. “They had a radio, but it failed very early on. That technology was still in its infancy back then. When Titanic sank four years prior to that, it carried a Marconi radio set, and that wasn’t effective enough, either.”

Coulthard goes on to explain that one of the reasons Shackleton’s radio was unfit for service was that “the men couldn’t get the antenna high enough. You imagine this great big dipole antenna hanging from the masts. Even then they couldn’t get it spread out enough to get a signal to shore. They were simply too far south”.

Smart boat

As far as his affection for the James Caird stretches, Coulthard admits that it is not the sort of craft in which you would ever wish to sail 800 miles. “It’s probably the most inadequate boat for crossing an ocean. But it is an incredibly smart piece of engineering. When you look at the old pictures, it just looks like a wooden mess cobbled together. But in fact, when you look at it in detail, it is an incredible survival capsule that was to ferry six men to South Georgia.”

Coulthard attempts to describe what it is like to experience what Shackleton’s sailors did a century ago. “Imagine yourself and five other people in the back of an estate car. You’ve got to live in that car for 17 days. You’re driving at 4mph for the whole time with the windows open through a rainstorm. You have to eat, live, go to the toilet all in that space.”

Being inside the boat for Coulthard was “so horrendous” that he would look forward to his turn to go up on deck to steer. “But after an hour on deck freezing to death and semi-hypothermic you actually look forward to going back. Outrageous, really.”

In 1916, the James Caird had neither support vessel nor satellite tracker. The only technology available to the navigator – Frank Worsley – was a sextant, a chronometer and a compass. Even in the early 20th century the sextant was woefully old-fashioned, having been around for centuries. However, it was an accepted method for calculating the angle between two objects (normally the sun and the horizon), which, when combined with the time, could allow the navigator to calculate a position that could then be marked on a chart. Worsley’s problem was that in 17 days at sea he only got a sighting of the sun on four occasions, which puts his achievement into perspective. “If you miss South Georgia there is another 3,500 miles before you reach South Africa, which they never would have done with the provisions they had.”

Coulthard says that on the centenary reconstruction they navigated in roughly the same way, “although there were some slight differences”. The first of these is that they didn’t use a 1916 almanac, preferring modern navigational celestial tables. “But the principle was the same: we used a sextant, a marine chronometer and an Admiralty compass. The Thomas Mercer boxed marine chronometer needed to be wound up every day, and it lost a few seconds every day, which we had to account for in our calculations. To use the sextant, our navigator Paul Larsen had to go out on a pitching deck. A huge challenge.”

The challenge meant that at one point Coulthard and his companions got blown 30 miles off course. “We’d made a mistake somewhere along the line, as we were all trying to compute these numbers in our heads. We didn’t have calculators and so we were trying to add degrees, minutes and seconds while trying to work out where we had gone wrong in the equation. We didn’t even have a slide rule. Just wet paper and a pencil. It was tricky.”

What would we do now?

One of the greatest technical achievements of the rescue mission was the set of structural modifications made to the James Caird ahead of her departure. Yet to truly understand just how skilled the crew’s carpenter Harry McNish was, Coulthard believes we need to project first into the modern way of doing things. “Today, we have the advantage of vast amounts of knowledge about new materials and systems that we can fit into boats.”

Coulthard then ponders aloud an elaborate thought experiment in which he maroons 28 men (the complement of Endurance) in the Antarctic with a team of engineers challenged to design a rescue boat that will take them from Elephant Island to South Georgia “across the most dangerous stretch of water on the planet”. The result, he believes, “would be a really high-spec, big-budget machine, so complex that it would take years to build. That’s because we use modern thinking and have to include health and safety. It would end up extraordinarily complicated.

“Now go back 100 years to the resources that Shackleton’s men had and the first thing that you find is that what appeared to be a very difficult technical challenge turned out to be very basic.” First you pick the sturdiest and most seaworthy of the boats, but it is completely open and exposed. To stop the water pouring in on an ocean voyage you need to build a deck. In order to do this, the sides of the James Caird needs to be raised. “You then create the deck from Venesta plywood packing cases, stretch canvas over the top and then seal all the edges and gaps with oil paint, supplied by the expedition artist George Marston.”

The sealant for caulking the seams was in fact a mixture of paint, flour and seal blubber, applied with a spatula. “Then, to make sure it doesn’t leak, you take the blood from the seal that you have just shot for dinner, for finishing off. Rubbing blood on the surface of the paint smoothes it over so the water will pass over it. If you leave it rough, the salt water will simply wash it out.”

The replica for the 2013 journey was named the Alexandra Shackleton after the explorer’s granddaughter, who stood as expedition patron. The replica currently under construction is in his in-laws’ garden, leading Coulthard to the conclusion that while in many respects it is a small boat, “it’s actually quite big when you see it in the garden”. The question has to be: why on earth should he again want to put himself through the process of reconstructing a boat for which there are no original drawings remaining?

“When we came back in 2013 the Alexandra Shackleton followed us on a cruise ship and ended up in Portsmouth. To see it among all the modern boats was an experience, because people would just walk straight past it. But I realised then that in terms of some of the technical aspects of the boat, I had arrived home with more questions than answers.”

By way of an example, Coulthard explains that nobody could satisfactorily explain what would happen should the replica capsize. “We’d planned for it of course, but we had never really trialled the boat sufficiently to find out for definite what would happen. It was only hypothesised and planned on paper.”

Yet the real incentive for Coulthard is to make the current project – he’s keeping a tight lid on what he will name it – more authentic than any previous efforts (there have been several, including a replica used in the Kenneth Branagh movie ‘Shackleton’). There were naturally some compromises to modernity in mind with the Alexandra Shackleton, “because we had to survive to tell our story. Shackleton did it out of necessity and we did it out of choice”.

Coulthard is left awestruck by the skill of the men involved, particularly McNish. “I’ve built two of these boats and I know how complex a task it is. To achieve what they did with only four basic tools, and for the boat to play such a part in the rescue is incredible.”